As a conventional plasma processing apparatus, there has been known a plasma processing apparatus including an evacuable processing chamber; a mounting table for mounting thereon a processing target in the processing chamber, the mounting table serving as a lower electrode; and an upper electrode disposed to face the mounting table (see, e.g., Japanese Patent Application Publication Nos. 2011-238825 and 2000-195935). In the plasma processing apparatus described in Japanese Patent Application Publication Nos. 2011-238825 and 2000-195935, by applying high frequency power between the upper electrode and the mounting table serving as the lower electrode, plasma processing is performed on a processing target such as a wafer disposed on the mounting table.
Further, the plasma processing apparatus described in Japanese Patent Application Publication Nos. 2011-238825 and 2000-195935 includes a plurality of lifter pins provided to protrude beyond and retract below the upper surface of the mounting table so as to move up the processing target from the mounting table or move down the processing target onto the mounting table. Further, the mounting table has pin holes for receiving the lifter pins therein. Further, the plasma processing apparatus described in Japanese Patent Application Publication No. 2011-238825 has gas holes for supplying helium gas for heat transfer between the backside of the processing target and the surface of the electrostatic chuck.
In order to prevent a discharge occurring between the mounting table and the processing target, the plasma processing apparatus described in Japanese Patent Application Publication No. 2011-238825 has lifter pins with cover portions provided at the top thereof. When the lifter pins are received in the pin holes, upper portions of the pin holes are in a state of being closed by the cover portions provided at the top of the lifter pins. Further, the plasma processing apparatus described in Japanese Patent Application Publication No. 2000-195935 has lifter pins, upper portions of which are formed in an inverted triangle or corrugated shape in order to prevent abnormal discharge generated by the plasma coming into the inside of the pin holes.
However, in the configuration disclosed in Japanese Patent Application Publication Nos. 2011-238825 and 2000-195935, there is provided a mechanism to move up and down the lifter pins in a vertical direction perpendicular to the backside of the processing target disposed on the mounting table for the function of lifting the processing target onto the mounting table. That is, a radial space required for moving up and down the lifter pins in the vertical direction. Thus, in some cases, it may be impossible to prevent abnormal discharge in the radial space. As a result, it may worsen the quality of the processing target and become a cause of yield deterioration.